A nuclear imaging tool, breast-specific gamma imaging (BSGI) — also known as molecular breast imaging (MBI) — employs a maneuverable camera to capture high-resolution functional images of the breasts.
Unlike mammography, BSGI is not affected by tissue density. It is a molecular imaging procedure that evaluates the metabolic activity of breast lesions through an injection of a radioactive tracer. Cancer cells absorb more of the tracing agent due to their higher metabolic activity and increased blood supply — so cancerous areas “light up” on BSGI.
No compression of the breast is necessary in a BSGI procedure, as the camera detects the tracing agent.
This modality does not replace mammography, but is an additional tool that physicians may use alongside mammography and ultrasound. It can help clarify results, or provide more specific information.
BSGI can be helpful when screening women at high risk, and in imaging hard-to-evaluate patients, like those with dense breasts, implants or scar tissue. It’s also useful when a patient feels an abnormality, but nothing is seen on mammography and/or ultrasound.